add TODOs to sketch out the rough plan for Spimr
update to readme
I think this is a better way to do controller/action-specific routes
generate QR code for checkin link, display it on spime/show. will
eventually need to restrict seeing the QR code to just the creator of the spime.
updated todos
switch to using SVG for spime QR codes, heroku's imagemagick is too
slow. SVG is coming out transparent background, so add a white
background in HTML. should figure out how to handle this by
using the rqrcode, ideally.